Where can I get The Chef, Angela and Sigrid?

The Chef and Angela are included in "Operation Cerberus", Sigrid is included in the original Core Set. This means you won't have any problems getting the Chef and Angela, but you'll probably have to invest some time and money to get Sigrid.

There are also premium versions of Sigrid that will soon be made available through Dust Models for a pretty penny.

Thanks again guys, I really appreciate the help.  And I am sorry if that was posted somewhere already.  Sigrid doesn't really seem that good so I will probably just skip her, but the others have potential.

 Sigrid is awesome, check out her damage against A2 when things get close 7dice! and when attached to a laser unit with berserk re-rolling misses for sustained fire, rerolling misses for berserk,  and re-rolling every hit again and again for using lasers, makes the laser grenadiers one of the best units in the game.

Major Mishap said:

Also, Sigrid plus Snipers is nasty - blanks hit + reroll on hits is a nasty combo that can cause massive amounts of damage.

Sigrid and Joe are going to sell for 40 for premium versions, which I wouldn't exactly consider a "pretty penny" for limited edition premium models  of almost impossible to find models. .. unless the penny you are paying with is just a brand new shiny, attractive looking penny, then you can call it a "pretty penny" lol. Many of the campaign boxes are 40-50 bucks for pretty much just getting 2 models and they are not premium editions, so to pay 40 for 2 highly sought after, limited edition, premium painted models of Joe and Sigrid is not a bad deal for 40 bucks if you ask me… especially if you happen to be one of the lucky people who get one before they (guaranteed) sell out right away. Once those premiums sell out, people will be asking me, "where can I get Sigrid" and I will give my best impression of Macho Man Randy Savage in the movie Spiderman and say "NOWHERE!"  :)